I think the most pressing issue is the concept. In the end, the concept boils down to "book that makes things real but makes things invisible to the reader too." Generally, things that manifest other things by writing in them are poorly received on the wiki, since they not only come off as overpowered, but they are generally uninteresting to read. I doubt that this idea would survive if it was posted.

I'd recommend going to the Ideas and Brainstorming board and getting your idea, or possibly another idea, refined there. You'll come out with a concept that can be easily worked with.

I feel like one of the bigger problems here is that two entire tests are expunged. You see, the reader wants to see what's under those blackboxes, and not seeing may disappoint them. Try to tell us what's under them; it will definitely help.

I'd also recommend reading the How to Write an SCP guide. It contains information about style and tone that you could probably apply to your future writing. I'd also recommend reading some newer SCPs, as they can provide some example of what the community is expecting nowadays. Here are some personal picks: